High field-effect mobility ZnO thin-film transistors with Mg-doped Ba0.6Sr0.4TiO3 gate insulator on plastic substrates

The authors report on the influence of Mg acceptor doping on the markedly reduced leakage current characteristics (<5×10−8A∕cm2 at 2MV∕cm) of Ba0.6Sr0.4TiO3 thin films. The suitability of room temperature deposited Mg-doped Ba0.6Sr0.4TiO3 films as gate insulators for low-voltage ZnO thin-film transistors (TFTs) (<6V) was investigated. All room temperature processed ZnO-TFTs on plastic substrates exhibited a high field-effect mobility of 16.3cm2∕Vs and a current on/off ratio of 6.4×104. The threshold voltage and subthreshold swing were 2.8V and 400mV/decade, respectively.